Time optimized radiation treatment

ABSTRACT

In one embodiment, a method includes receiving treatment information relating to a treatment plan for proton- or ion-beam therapy intended to irradiate a target tissue; receiving machine-limitation information relating to one or more limitations of one or more machines involved in the proton- or ion-beam therapy; determining a time-optimized beam current for a proton or ion beam based on the treatment information and the machine-limitation information, wherein the time-optimized beam current minimizes the time required to deliver a required quantity of monitor units to one of a plurality of spots, wherein each of the plurality of spots is a particular area of the target tissue; and delivering the time-optimized beam current to the particular area.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.16/900,594 filed on Jun. 12, 2020, pending, which is a continuation ofU.S. patent application Ser. No. 16/091,515 filed Oct. 4, 2018, pending,which is the national stage of International Patent Application No.PCT/EP2017/000420, filed Apr. 4, 2017, which claims priority to, and thebenefit of, U.S. Provisional Patent Application No. 62/318,692, filedApr. 5, 2016. The entire disclosures of all of the above applicationsare expressly incorporated by reference herein.

FIELD

This disclosure generally relates to radiation treatment.

BACKGROUND

Proton therapy, also called proton beam therapy, is a type of radiationtreatment that uses protons rather than X-rays to irradiate diseasedtissue. Although this disclosure focuses on describing the embodimentsin terms of a therapy involving a proton beam (i.e., “proton therapy”),it contemplates therapies with other suitable ion beams (i.e., “iontherapy,” generally). One advantage of therapy using high energy protonor ion particles is that their path though the tissue stops at a certaindepth, depending of the energy of the particle. On their path throughthe tissue the particles interact with the matter of the tissue and loseenergy to the matter of the tissue. Since the particles increasinglylose energy on their path through the tissue, and since the rate ofenergy loss is higher with decreasing energy of the particles, theparticles lose most of their energy at or toward the end of their paththrough the matter of the tissue, right before they stop. The highenergy deposition loss of charged particles at the end of their travelpath through the matter of the tissue is called the “Brag Peak.”Furthermore, charged particles may be actively steered in a transversedirection (which may be described in x- and y-coordinates) of theparticle travel path. By the superposition of charged particles withdifferent energies and by specifying x- and y- positions, one canachieve better three-dimensional dose conformity than with X-rayradiation therapy.

SUMMARY

In particular embodiments, beam currents of a proton or ion beam, or thenumber of protons or ions per time segment, may be adjusted to minimizethe time it takes to irradiate a target area with radiation. Minimizingthe treatment time may be beneficial not only for the convenience of thepatient and the treating doctor, but also for efficacy and safety, forexample in such cases where the patient is required to remain still(e.g., for breath-hold techniques that may be required in destroyingtissue within the lungs) or where a target tissue is a moving target.The beam currents may be adjusted according to a treatment plan and oneor more limitations to the treatment machine that produces the proton orion beam and delivers and monitors the radiation dose. The treatmentplan may be based on one or more computerized tomography (CT) images,and/or other suitable images derived from a suitable imaging technique,of the target area of the patient's body (e.g., a cancerous tumor), andmay include one or more prescriptions for an amount of radiation todeliver to the target area, as well as multiple locations within thetarget area to deliver the radiation.

Proton or ion therapy combined with a modulated spot-scanning method, or“pencil-beam scanning” method, that spot scans a treatment zone forirradiation carries the benefit of better three-dimensional doseconformity than known therapy methods on the market. With the modulatedspot scanning technique, each prescribed x and y position in anisocenter plane may be irradiated individually with respect toprescribed monitor units and energy values. These prescribed values maybe listed in a treatment plan (e.g., created by a doctor). The number ofspots in a treatment plan may be relatively high in many cases. In orderto keep the total irradiation time as short as possible, the algorithmdescribed herein may be employed.

In order to deliver the calculated dose of radiation, the treatment planmay need to be converted to machine parameters, like beam currents ofthe proton or ion beam, or the number of protons or ions per timesegment, magnet currents, and the like. A specialized software may beused to generate the treatment plan. A drawback of existing methods ofdeveloping treatment plans is that they cannot predict or take intoaccount durations of exposure (e.g., a duration for each of the spots ofa target volume, a duration for each field, a duration for each layer)while developing the treatment plan. The duration, as well as thesequence of the spots, may play an important role in mitigating motionof a target volume during irradiation (e.g., natural organ movementand/or the respiratory or cardiac cycles). An algorithm may be appliedwhich calculates the beam currents of the proton or ion beam, or thenumber of protons or ions per time segments such so that the patient istreated as fast as possible, taking into consideration all the treatmentmachines' limitations. In addition the algorithm may determine theduration of each spot of a field, taking into account the time-optimizedbeam currents of the proton or ion beam, or the time-optimized number ofprotons or ions per time segments. The determined durations of each spotand of the whole field can be taken into account in developing thetreatment plan. An algorithm may be applied to adjust the beam currentsof the proton or ion beam, or the number of protons or ions per timesegments such that the patient is treated as fast as possible, takinginto consideration all the treatment machines' limitations. Thealgorithm may also specify the beam currents of the proton or ion beam,or the number of protons or ions per time segment, at each spot and ateach layer of the target area.

Although this disclosure focuses on using proton beam therapy toirradiate diseased tissue (e.g., to destroy at least a portion thereof),it contemplates irradiating any suitable tissue (e.g., other undesirabletissue) using the methods described herein. The algorithms describedherein may be executed using any suitable computing system, orcomponents therein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates example depth-dose distributions for X-rays andprotons (or ions).

FIG. 2 illustrates an example apparatus of the treatment machine forirradiating a target in a time-optimized manner.

FIG. 3 illustrates an example magnet system of the treatment machine inthe accelerator, energy selection system, beam transfer line, orscanning system for irradiating a target in a time-optimized manner.

FIG. 4 illustrates an example scanning system of the treatment machinefor irradiating a target in a time-optimized manner.

FIG. 5 illustrates an example of the treatment machine for routing aproton beam to multiple treatment locations.

FIG. 6 illustrates an example block diagram of the inputs and outputsfor an algorithm used for irradiating a target in a time-optimizedmanner.

FIG. 7 illustrates an example block diagram of system components of thedescribed treatment system and their example functionalities.

FIG. 8 illustrates an example block diagram of the handling of inputsand the specific outputs for an algorithm used for irradiating a targetin a time-optimized manner.

FIG. 9 illustrates an example computer system.

DESCRIPTION OF THE EMBODIMENTS

In particular embodiments, beam currents of the proton or ion beam, orthe number of protons or ions per time segment, may be adjusted tominimize the time it takes to treat a target area with radiation. Thebeam currents of the proton or ion beam, or the number of protons orions per time segment may be adjusted according to a treatment plan andone or more limitations to the treatment machine equipment that producesthe proton or ion beam and delivers and monitors the radiation dose. Thetreatment plan may be based on one or more CT images, and/or othersuitable images derived from a suitable imaging technique, of the targetarea of the patient's body (e.g., a cancerous tumor), and may includeone or more prescriptions for an amount of radiation to deliver to thetarget area, as well as multiple locations within the target area todeliver the radiation.

In order to deliver the prescribed dose of radiation, the treatment planmay be converted to machine parameters (e.g., beam currents of theproton or ion beam or the number of protons or ions per time segment tobe emitted by the accelerator, magnet currents, settings to achieve theprescribed energy of protons or ions at the target volume, measurementrange of dose monitor system, etc.). This conversion may take intoaccount the limitations of the treatment machines' equipment thatproduce the proton or ion beam and deliver and monitor the radiationtreatment. For example, a particular treatment machine may have an upperlimit for the beam currents of the proton or ion beam, or an upper limitfor the number of protons or ions per time segment (e.g., as may limitedby the devices of the accelerator, the energy selection system, and/orthe beam transfer line). As another example, the equipment of the dosemonitoring system may have upper and lower limits for the beam currentof the proton or ion beam, or may have upper and lower limits of thenumber of protons or ions per time segments (e.g., it may be out of themeasurement range). As another example, the equipment of the beamposition and beam shape monitoring system may have upper and lowerlimits for the beam current of the proton or ion beam, or may have upperand lower limits of the number of protons or ions per time segments(e.g., it may be out of the measurement ranges). In particularembodiments, an algorithm may be applied to adjust the beam currents ofthe proton or ion beam, or the number of protons or ions per timesegments so that the treatment time is as short as possible, taking intoconsideration all the machines' limitations and the minimum amount oftime needed to complete the irradiation of a spot or layer. For example,the beam current may be set as high as possible for either each layer oreach spot, in order to minimize the treatment time and to accommodatethe treatment machine limitations. In particular embodiments, thealgorithm may specify the beam currents of the proton or ion beam, orthe number of protons or ions per time segments for each spot and/or foreach layer of the target area. For example, the algorithm may specifybeam currents of the proton or ion beam, or the number of protons orions per time segments for each layer, where all spots in the same layerare irradiated with the same beam current of the proton or ion beam, orwith same the number of protons or ions per time segments. As anotherexample, the algorithm may specify the beam currents of the proton orion beam, or the number of protons or ions per time segments for eachspot, where all spots in the field may be irradiated with different beamcurrents.

A specialized software may be used to generate the treatment plan. Adrawback of existing methods of developing treatment plans is that theycannot predict or take into account durations of exposure (e.g., aduration for each of the spots of a target volume, a duration for eachfield, a duration for each layer) while developing the treatment plan.The duration, as well as the sequence of the spots, may play animportant role in mitigating motion of a target volume duringirradiation (e.g., natural organ movement and/or the respiratory orcardiac cycles). An algorithm may be applied which calculates the beamcurrents of the proton or ion beam, or the number of protons or ions pertime segments such so that the patient is treated as fast as possible,taking into consideration all the treatment machines' limitations. Inaddition the algorithm may determine the duration of each spot of afield, taking into account the time-optimized beam currents of theproton or ion beam, or the time-optimized number of protons or ions pertime segments. The determined durations of each spot and of the wholefield can be taken into account in developing the treatment plan.

FIG. 1 illustrates example depth-dose distributions for X-rays andprotons (or ions). Proton or ion therapy may be superior to x-rayradiation therapy in terms of its ability to prevent damage tosurrounding healthy tissue. X-axis 101 shows the depth of the particlesand y-axis 102 shows the proportional radiation dose delivered at agiven depth. The proportional dose of radiation delivered by the photonsin x-ray radiation therapy is shown by photon dose distribution line103. Photon dose distribution line 103 peaks at a low depth and thengradually tapers out. To increase the radiation delivered at a desireddepth, damage to the healthy tissue above the tumor may beproportionally increased. In comparison, proton (or ion) dosedistribution line 104 minimizes the radiation delivered before and afterthe target and delivers nearly all of its energy in a given window ofdepth. The peak of the proton or ion dose distribution line is calledthe Bragg peak.

Protons or ions may be accelerated to suitable energy using a particleaccelerator. Some common types of particle accelerators are cyclotrons(e.g., normal- or super-conducting cyclotrons), synchrotrons (e.g.,normal- or super-conducting synchrotrons), and synchrocyclotrons (e.g.,normal- or super-conducting synchrocyclotrons). These accelerators maydepend on the interplay of magnetic and electric fields. Synchrotronsmay accelerate particles through a path having a constant radius andadjust the magnetic and electric fields as the particles gain momentum.Cyclotrons may accelerate charged particles using a high-frequencyalternating voltage. A perpendicular magnetic field may cause theparticles to move in an expanding spiral wherein they re-encounter theaccelerating voltage. When the particles reach a predetermined radiusthey may be guided out of the cyclotron in an accelerated state.

When a patient comes in for cancer treatment, a CT scan may beperformed, and/or other suitable imaging technique, to determine thesize, shape, and location of a diseased tissue. Images from the CT scan(or other suitable technique) may produce a three-dimensional image ofdiseased tissue in the patient's body. Using the images, a treatmentplan for that patient is produced. A specialized software to aid withthe development of the treatment plan may be used. The treatment planmay define, among other things, (1) the treatment volume or a targetvolume; (2) the radiation dose; (3) location to deposit radiation; and(4) field and fraction parameters. In particular embodiments, thespecialized software may include a means for rendering a virtualvisualization of time dependent application during the treatmentplanning process (prior to treatment). The software may allow thedoctors to evaluate treatment efficacy of one or more potentialtreatment plans. For example, it may render a simulated overlay oftarget movement (e.g., caused by the patient's breathing or otheraction), and may also simulate the effects of applying different dosesto different areas at different times.

“Treatment volume” refers to the entire volume that will be subject toradiation—this may include both the “target volume” (e.g., the volumethat defines a diseased tissue) and the surrounding healthy tissue andorgans. With proton or ion beam therapy, radiation delivered tosurrounding healthy tissue and organs may be minimized, so treatmentvolume and target volume may be roughly equivalent.

The radiation dose may be measured in gray units. One gray is defined asthe absorption of one joule of radiation energy per one kilogram ofmatter. Based on the defined target tissue (e.g., a diseased tissue) andthe prescribed radiation dose the specialized software to aid with thedevelopment of the treatment plan determines the energy per spot, thenumber of monitor units (or in some cases the number of protons or ions)per spot, and the beam position in x- and y-coordinates in an isocenterplane per spot. Additional parameters (e.g. incident angle of the beam,position of the patient, etc.) are determined using the specializedsoftware to aid with the development of the treatment plan.

A treatment plan may contain the parameters for each field. A field isthe direction from which the target volume gets irradiated, i.e. thedirection from which the beam is shot or the incident angle, and thepatient position with respect to the incident angle. A patient mayreceive radiation with one or multiple fields. For example, if a protonbeam is delivered to the body from directly above the body (e.g., 0degrees), that may be a first field. At a second time, a second protonbeam may be delivered from 30 degrees, and this may be a second field.At a third time, a third proton beam may be delivered from 60 degrees,and this may be a third field.

Most treatments of diseased tissue with a prescribed total dose aresplit into several “fractions”. Each fraction will irradiate a“fraction” of the total prescribed dose. For example, a prescribed totaldose may be broken up over 20 to 30 “fractions” that may occur over thecourse of several weeks.

An example treatment plan may include a target volume that defines avolume of the diseased tissue that is to be targeted by the proton- orion-beam therapy; a set of spots that specify a prescribed beam positionin x- and y-coordinates per spot at an isocenter, wherein the x- andy-coordinates are transversal to a beam direction, a prescribed energyof the proton or ion beam per spot, and a prescribed amount of monitorunits per spot; a set of field parameters that specify a direction fromwhich the proton or ion beam is to be shot, a position of the targetvolume, and treatment specific parameters for one or more fields; and afraction parameter that specifies a portion of the radiation dose thatis to be delivered for a given radiation session.

In order to deliver the prescribed dose of radiation, the proper beamcurrents of the proton or ion beam, or the number of protons or ions pertime segment are calculated for each fraction of radiation dose, analgorithm may calculate the beam currents of the proton or ion beam, orthe number of protons or ions per time segment for each energy layer.This means that all spots on the same energy layer may be irradiatedwith the same the beam currents of the proton or ion beam (or the samethe number of protons or ions per time segment). The algorithm may alsotake into account the treatment machine parameters and limitations. Thebeam current of the proton or ion beam (or the number of protons or ionsper time segment for a given energy layer) may be calculated by takingthe ratio of “monitor units” (e.g., how many protons are necessary toeffectively treat a location on the tumor) to the “minimum spotduration” (e.g., the minimum time to stay at a spot before moving to thenext spot). The algorithm may check whether this ratio is larger thanthe upper limit of the dose monitor system or the beam position and beamshape monitor system. If so, the beam current, or the number of protonsor ions per time segment, may be set to the upper limit. The algorithmmay also check whether any of the calculated beam currents, or thecalculated number of protons or ions per time segment, is higher thanthe upper limit of the accelerator. If so, the beam current, or thenumber of protons or ions per time segment, may be set to the upperlimit.

FIG. 2 illustrates an example apparatus for irradiating a target in atime-optimized manner. System 200 comprises cyclotron 201, which isconfigured to generate a proton beam. In particular embodiments,cyclotron 201 may be a superconducting cyclotron. The energy level forprotons in the proton beam may be selected using energy selection system202. Energy selection system 202 may be capable of setting an energylevel continuously up to the fixed energy of the accelerated protons bythe cyclotron. In particular embodiments, this energy selection may bebased on a first information which may be deterministic informationprovided by the treatment plan or provided by a system that derives thisinformation. Scanning system 203 may guide the proton beam to a locationon target 204 using a magnet system. In particular embodiments, scanningsystem 203 may guide the proton beam according to a second informationwhich may be deterministic information provided by the treatment plan orprovided by a system that derives this information. In particularembodiments, system 200 may be capable of three-dimensional spotscanning or pencil beam scanning. In these embodiments, the energy ofthe protons in the proton beam may be set to the prescribed values inthe treatment plan for each spot, and to the prescribed transversalcoordinates of the beam for each spot by adjusting the magnet system ofthe scanning system. Adjusting the energy of the beam may allow controlof the depth at which the Bragg Peaks of the accelerated protons arelocated. The increased flexibility made available throughthree-dimensional spot scanning may greatly improve the precision of thedose delivered to a patient so as to maximize dose delivery to a tumorand minimize damage to healthy tissue.

Spot scanning of target 204 can be conducted in accordance with severalvariant methodologies. In particular embodiments, target 204 may be atumor and the location to which the proton beam is guided may beselected based on patient location data regarding a specific patient whois undergoing proton radiation therapy. The patient location data mayinclude information about the location of certain anatomical structureswithin a patient and may also include the location of a tumor within thepatient's body. Spot scanning of target 204 (e.g., a portion of diseasedtissue) may be conducted in multiple sessions, “fractions”, with thesame or variant spot scanning patterns. In particular embodiments,scanning system 203 and energy selection system 202 may both alter theirvalues during a given application of protons so that three-dimensionalspot scanning may be achieved. In particular embodiments, the beamcurrent of the proton beam or the number of protons per time segment maybe altered along with the energy of the proton beam and/or with thetransversal coordinates to more accurately control the delivery ofradiation to the target at a specific location. In particularembodiments, scanning system 203 may adjust the location of beamdelivery during an application while the energy level remains constantso that the protons may be applied in a transversally varying mannerwhile the depth of the Bragg Peak may remain constant or nearlyconstant. In order to have a medically significant effect on tumors, asingle session of proton radiation therapy may not need to be great induration. For example, the irradiation of a single field of a fractionmay take several seconds or even less than one second.

System 200 may additionally comprise a beam transfer line 205. Inparticular embodiments, beam transfer line 205 may have multiplejunctions having magnets or other devices for guiding the beam throughvarious paths. In particular embodiments, certain paths may be shut-offwhile others remain open. Beam transfer line 205 may lead the protonbeam from Energy Selection System 202 to Scanning System 203, or theScanning System may be in between the devices of the beam transfer line.In particular embodiments, target 204 may be a diseased tissue in apatient's body or some other target for proton beam irradiation.

FIG. 3 illustrates an example magnet system 300 comprising a magnetstructure 310 and magnet power supply 303. A magnet system may be partof the accelerator, energy selection system, beam transfer line, and thescanning system. Referencing FIG. 3 and FIG. 4, scanning system 400 maycomprise a magnet system 300 used to guide proton beam 302. Magnetstructure 301 may be caused to alter its magnetic field to guide themagnet in transversal x- and y-directions. In particular embodiments,power may be provided to magnet structure 301 through magnet powersupply 303. In particular embodiments, magnet power supply 303 may becontrolled based on the energy of the proton beam and the target beamposition, x- and y-directions, at the target.

FIG. 4 illustrates an example scanning system for irradiating a targetin a time-optimized manner. Scanning system 400 may comprises a magnetstructure 401 used to guide the proton beam. In particular embodiments,magnet structure 401 may comprise two scanning magnets as shown byy-directional magnet 402 and x-directional magnet 403. In particularembodiments, the magnets may be powered by separate power supplies asshown by first magnet power supply 404 and second magnet power supply405. Y-directional magnet may be capable of steering the proton beam ina transversal y-direction. X-directional magnet 403 may be capable ofsteering the proton beam in a transversal x-direction. In particularembodiments, a magnet structure may comprise one scanning magnet, whichmay be a bi-directional magnet. In particular embodiments, thebi-directional magnet may include two pairs of coils—one for thex-direction and one for the y-direction. In particular embodiments, thecoils of the bi-directional magnet are powered by separate powersupplies. The bi-directional magnet may be capable of steering theproton beam in a transversal y-direction and a transversal x-direction,as necessary.

In particular embodiments, the scanning system may additionally comprisea transition ionization chamber such as transition ionization chamber406. This transition ionization chamber may be interspersed betweenmagnet structure 401 and target 407 along proton beam path 408.Transition ionization chamber 406 may be configured to measure the dosedelivered to target 407, i.e., it may work as the dose monitor system.In particular embodiments, the dose delivered may be tracked for aparticular location on target 407. In particular embodiments, the dosedelivered may be tracked for the entire target 407. In particularembodiments, transition ionization chamber 406 may be a multi-stripionization chamber comprising several millimeter-wide strips ofconductive foil connected to electronic sensors. Multi-strip ionizationchamber 406 may be configured to measure an actual beam position andbeam shape on target 407 relative to the targeted location.

In particular embodiments, the data collected by transition ionizationchamber 406 can be applied for various uses. As shown in FIG. 4, thecollected data could be sent to real-time processing unit 409. Inparticular embodiments, real-time processing unit 409 may useinformation regarding the beam position, dose or monitor units,treatment duration, and patient location data such as the depth of thetumor to direct magnet structure 401 so as to optimize the irradiationof target 407. For example, real-time processing unit 409 may determinethat the beam position does not match the desired location and maycompensate for this deviation (e.g., by adjusting the beam position) tomore accurately match the beam position with the desired location. Asanother example, real-time processing unit 409 may take inpatient-specific data in real-time regarding the position of the tumorand adjust the location to which the proton beam is directed, and/oradjust the energy of the proton beam to affect penetration depth. Inparticular embodiments, real-time processing unit 409 may deliver afirst information item to energy selection system 202. For example, thisfirst information item may be the depth of the tumor in a patientundergoing proton radiation therapy or the proton beam energy. Inparticular embodiments, real-time processing unit 409 may deliver asecond information item to other components in scanning system 400. Forexample, this second information item may be the beam position andtarget dose or data derived from beam position and target dose. In theseexamples, the system may make adjustments based on the firstinformation, the second information, and/or other suitable real-timeinformation. Real-time processing unit 409 therefore may allow forreal-time adjustment of the beam position, beam currents or number ofprotons or ions per time segment, and Bragg peak depth based on patientspecific information and actual measurement the proton beam'scharacteristics and location. In particular embodiments, the adjustmentmay be performed automatically within the treatment machine, in responseto an external device, or in response to an input by an operator of thesystem. In particular embodiments, the data collected by transitionionization chamber 406 could be output from the system for external use.In particular embodiments, the real-time information may include areal-time virtual visualization of the proton beam therapy.

FIG. 5 illustrates an example system for routing proton beams tomultiple locations. FIG. 5 illustrates system 500. System 500 maycomprise a cyclotron 501 and an energy selection system 502. System 500may additionally comprise a beam transfer line 503. In particularembodiments, beam transfer line 503 may have multiple junctions havingmagnet systems or other devices for guiding the beam through variouspaths. In particular embodiments, certain beam paths may be shut offwhile others remain open. Beam transfer line 503 may guide the beam topatient treatment room 504, which may have first scanning system 505 andfirst target 506. In particular embodiments, target 506 may be a tumorin a patient's body or some other target for proton beam irradiation.Beam transfer line 503 may also guide the beam to second patienttreatment room 507 which may have second scanning system 508 and secondtarget 509. In particular embodiments, scanning system 505 or scanningsystem 508 may have characteristics in accordance with those of scanningsystem 203. The treatment machines comprising the two systems may havetreatment machine limitations that are same or different. In a casewhere the two systems have different treatment machine limitations, thedisclosed algorithm may calculate different optimized beam currents ornumber of protons or ions per time segment and irradiation times (e.g.,setting the beam current or number of protons or ions per time segmentof each system to the upper limits of their respective treatmentmachines). Although FIG. 5 only illustrates a system for routing protonbeams to two scanning systems, this disclosure contemplates a system forrouting proton beams to any suitable number of scanning systems.

In particular embodiments, energy selection system 502 may havecharacteristics in accordance with those of energy selection system 202.In particular embodiments, energy selection system 502 may be able toreceive patient specific information and proton beam related informationfrom processing units in scanning system 505 and scanning system 508 aswell as from other scanning systems to which beam transfer line 503 isconnected. In particular embodiments, patient treatment room 504 andpatient treatment room 507 may be separate locations in the samefacility. In other embodiments, they may be separate locations indifferent facilities that still utilize the same cyclotron 501. Using asingle cyclotron in this manner may allow for the cost-effectiveutilization of the cyclotron.

FIG. 6 illustrates an example block diagram of the inputs and outputsfor an algorithm used for irradiating a target in a time-optimizedmanner. Input parameters 610 may include the treatment plan and thelimitations of the particular treatment machines (e.g., treatmentmachine parameters) that are being used to produce the proton or ionbeam and to deliver and monitor the radiation treatment. Such treatmentmachines may include any or all of the treatment machines discussedherein, or any other treatment machine that is used in radiationtreatment. The treatment plan may include the target volume, thetreatment volume, one or more locations on the tumor to deliverradiation (e.g., specified by a set of energy per spot, monitor units ornumber of proton or number of ions per spot, x-y coordinates at anisocenter for each spot), field and fraction parameters, a recommendedbeam current (e.g., the beam current to be used without accounting formachine limitations), and the time of exposure. These factors areexplained herein.

The machine parameters may include any combination of the followingparameters: minimum spot duration (e.g., the minimum time to apply abeam current to a spot before moving on to the next spot); beam currentor the number of protons or ions per time segment at isocenter; beamcurrent or the number of protons or ions per time segment from theaccelerator; monitoring limits or tolerances for the monitor unit;monitoring limits for the scanning magnet currents; and monitoringlimits or tolerances for the beam position and beam shape. The signalsof the dose monitor system, beam position monitor system, and beam shapemonitor system may have upper and lower limits. For example, there maybe upper and lower limits on the beam current or the number of protonsor ions per time segment (e.g. measurement range). These limits maydepend on the beam energy at isocenter, and the dose and positionmonitors parameters themselves); and the beam current of the treatmentmachine (e.g., the treatment machine may have an upper limit for a beamcurrent; this may depend on the beam energy).

From the defined target volume and the prescribed radiation dose thespecialized software to aid with the development of the treatment plandetermines the energy per spot, the number of monitor units per spot,and the beam position in x and y in the isocenter plane per spot.Instead of monitor units per spot (see IEC 60601 technical standards),“Scan Spot Meterset Weights” per spot (see NEMA DICOM RT standard), orin some cases the number of protons or ions per spot are given by thetreatment plan. Spot scanning may deliver a planned irradiation with agiven spot monitor unit, position, and energy. Algorithm 620 mayminimize the irradiation time for which the monitor units at each spotis applied. This may occur in at least two different ways: (1) applyradiation to each single spot in the treatment plan with the beamcurrent being adjusted for each energy layer individually; or (2) applyradiation to each single spot in the treatment plan, with the beamcurrent being adjusted for each single spot. The first way may irradiateeach energy layer as fast as possible; the second way may irradiate eachspot as fast as possible.

Algorithm 620 may calculate the beam current (number of protons persecond) or rate of monitor units for each spot separately and takinginto account the treatment machine parameters. The “beam current” or“rate of monitor units” may be calculated for each spot by the ratio of“monitor units” (e.g., prescribed by the treatment plan) to “minimumspot duration” (e.g., the minimum amount of time to stay at a spotbefore moving to the next spot). This “beam current” or “rate of monitorunits” may need to be checked if the value of the ratio is larger thanthe upper limit of dose monitor system and the beam position and beamshape monitor system. If this is the case the “beam current” or “rate ofmonitor units” may be set to the upper limit. In addition, it may benecessary to check if this “beam current” or “rate of monitor units” ishigher than the upper limit of the treatment machine (e.g., a proton orion accelerator). If this is the case the “beam current” or “rate ofmonitor units” may be set to the upper limit. Similarly, if this new“beam current” or “rate of monitor units” is lower than a lower limit(e.g., a minimum beam current) of the dose monitor system and the beamposition and beam shape monitor system or of the irradiation machine, anerror message may be displayed to the user, with the information of theproblem. This error case may not occur when all devices of the treatmentmachine are designed, installed and commissioned correctly.Alternatively or additionally, the beam current may be set to the lowerlimit. The algorithm may also check for beam current or number of protonor ion per time segment limitations on the energy selection system andthe beam transfer line, which refers to the trajectory of the protonbeam. For example, it may check for limitations with respect tomeasuring the beam with the dose monitor system and the beam positionand beam shape monitor system or generating the beam with the treatmentmachine.

Algorithm 620 may calculate the beam current (number of protons persecond) or rate of monitor units for each energy layer separately (e.g.,all spots with the same energy may be irradiated with the same “beamcurrent” or “rate of monitor units” and taking into account thetreatment machine parameters). The “beam current” or “rate of monitorunits” for a set of spots within the same energy layer may be calculatedby the ratio of “monitor units” to “minimum spot duration.” Inparticular embodiments, the smallest spot monitor unit value in a set ofspot monitor values corresponding to the set of spots may be used. This“beam current” or “rate of monitor units” may need to be checked if thevalue of the ratio is larger than the upper limit of the dose monitorsystem, the beam position, and/or the beam shape monitor system. If thisis the case the “beam current” or “rate of monitor units” may be set tothe upper limit. In addition, it may be necessary to check if this “beamcurrent” or “rate of monitor units” is higher than the upper limit ofthe treatment machine (e.g., a proton or ion accelerator). If this isthe case the “beam current” or “rate of monitor units” may be set to theupper limit. If this new “beam current” or “rate of monitor units” islower than a lower limit (e.g., a minimum beam current) of the dosemonitor system and the beam position and beam shape monitor system or ofthe irradiation machine, an error message may be displayed to the user,with the information of the problem. It needs to be noted, that thiserror case may not occur when all devices of the treatment machine aredesigned, installed, and commissioned correctly. The algorithm may alsocheck for beam current or number of proton or ion per time segmentlimitations on the energy selection system and the beam transfer line,which refers to the trajectory of the proton beam. For example, it maycheck for limitations with respect to measuring the beam with the dosemonitor system and the beam position and beam shape monitor system orgenerating the beam with the treatment machine.

The two inputs (e.g., the treatment plan and treatment machinelimitations) may be fed into algorithm 620, and the algorithm mayprocess the inputs and produce an adjusted beam current or adjustednumber of protons per time segment for the accelerator, and the beamcurrent at dose monitor system and the beam position and beam shapemonitor system as output parameter 630. This adjusted beam current maytake into consideration the treatment plan and the machine limitations,and may allow for radiation treatment to be completed with a minimumamount of time.

FIG. 7 illustrates an example block diagram of system components of thedescribed treatment system 700 and their example functionalities. Inparticular embodiments, the energy of the proton (or ion) beam may setby an accelerator 710 of the treatment machine itself, an energyselection system 720, and/or a range modulation system 760 (e.g., at ornear the location of the patient). In particular embodiments, the energyselection system 720 may modify the energy of the proton (or ion) beamdelivery from the accelerator. In particular embodiments, in order toguide the beam from the accelerator 710 to the nozzle 750, the treatmentsystem may be equipped optionally with a beam transfer line 730. Thebeam transfer line 730 may have multiple junctions having magnets and/orother devices for guiding the proton or ion beam through various pathsto one or more nozzles. In particular embodiments, the energy selectionsystem 720 of the treatment system 700 may consist of devices usedtogether with the beam transfer line 730.

In particular embodiments, the range modulation system 760 may modifythe beam energy of the proton (or ion) beam at the nozzle 750 (which maybe upstream or downstream the primary and secondary dose monitor system(e.g., IEC 60601-2-64)), right before the beam hits a treatment area ofthe patient, and/or at any other suitable location.

In particular embodiments, the nozzle may comprise a magnet structurewhich may have the capability to steer the proton (or ion) beam in atransversal y-direction and transversal x-direction. In addition, inparticular embodiments, the nozzle may comprise the primary andsecondary dose monitor systems (e.g., IEC 60601-2-64), and a beamposition and beam shape monitor system. The components of the treatmentsystem may be either fully or partly installed at position 740 (whichmay be a gantry or a fixed beam room). The gantry may be a mechanicalstructure that facilitates the performing of the irradiation of thetreatment volume from different directions. A fixed beam room may be aroom that facilitates the performing of the irradiation of the treatmentvolume from one direction.

In particular embodiments, using the modulated spot scanning technique,the treatment system 700 may irradiate each prescribed x and y positionin an isocenter plane individually with the prescribed monitor units,and with respect to the prescribed energy of the proton (or ion) beam.The prescribed energy of the proton or ion beam may be set in anysuitable manner (e.g., as described herein). The prescribed values maybe listed in a treatment plan (e.g., one that is specific to the patientor a group of patients). In particular embodiments, the treatment system700 may adjust the beam current for each spot, or each energy layerrespectively, as may have been calculated,

FIG. 8 illustrates an example block diagram of the handling of inputsand the specific outputs for an algorithm used for irradiating a targetin a time-optimized manner. Similar to FIG. 6, FIG. 8 provides only ahigh-level description of an example embodiment.

In particular embodiments, when the beam current “I_(beam)” is set foreach layer or energy E, the beam current at the dose monitor system foreach layer may be calculated as follows. For each layer “layer_number,”the beam current “I_(beam) (layer_number)” may be calculated by thefraction of the smallest monitor unit value “MU_(min)” and the minimumspot duration “T_(min),” and may be multiplied optionally with a factor“F”, which describes the energy losses of the proton or ion beam in thedose monitor system or any other dose monitor system specificcorrection. An example of a generalized, high level layer algorithm isdescribed below:

i. Part 1 of Example Layer Algorithm:

l_(beam)(layer_number) = MU_(min)(layer_number)/T_(min) * F

b. In the next steps the treatment system limitations may be taken intoaccount. As an example, the measurement range of the dose monitor systemand the beam position and beam shape monitor system, “I_min_monitors”and “I_max_monitors”, are considered:

  i.    Part 2 of example layer algorithm: If l_(beam)(layer_number) >l_max_monitors then ii.    l_(beam)(layer_number) = l_max_monitors iii.   Endif iv.    If l_(beam)(layer_number) < l_min_monitors then v.   Error_with_identifier vi.    Endif

c. As a further example, the maximum or minimum beam current at the dosemonitor system limited by the devices of the accelerator, the energyselection system, and/or beam transfer line are considered, “I_min” and“I_max.” For example, I_min may be the minimum possible extracted beamcurrent of the accelerator times the so-called transmission of theenergy selection system and beam transfer line, and I_max may be themaximum possible extracted beam current of the accelerator times theso-called transmission of the energy selection system and beam transferline.

  i.    Part 3 of example layer algorithm: If l_(beam)(layer_number) >l_max then ii.    l_(beam)(layer_number) > l_max Ifl_(beam)(layer_number) < l_min_monitors then 1.  Error_with_identifieriii.    Endif iv.    Endif v.    If l_(beam)(layer_number) < l_min thenvi.    Error_with_identifier Endif

In the example algorithm directly above, the error messages should notoccur if the machine configuration of the treatment planning system, thetreatment system, and the measurement range of the treatment system dosemonitor system are designed correctly. Although the example algorithmconsiders particular example system limitations, any other suitablelimitations can be taken into account by plugging them into any suitablecombination of Parts 2 and 3 of the example algorithm.

In the next step, the algorithm calculates either the beam current (ornumber of protons or ions per second) from the accelerator,I_(accelerator), or the number of extracted protons or ions per timesegment from the accelerator, N_(accelerator). In the equations below,“S” is the ratio between the beam current at the dose monitor systemI_(beam) and the beam current from the accelerator I_(accelerator), and“time_segment” is the duration of one or more time segments during whichthe accelerator extracts protons or ions. S may depend on the energy,the Gantry angle, and/or the beam spot size.

a. Part 4 of Example Layer Algorithm:

l _(accelerator)(layer_number) = l_(beam)(layer_number)/S

or

b.

N _(accelerator)(layer_number) = l_(beam)(layer_number)/S * time_segment

c. Part 5 of Example Layer Algorithm:

d.

T(spot_number) = MU(spot_number)/  l_(beam)(layer_number) * F

The ratio “S” depends of the implementation of the treatment machine.For example, it can depend on the beam energy of the layer, one or moretreatment machine limitations, and/or one or more treatment machineparameters. T(spot_number) is the duration of each spot during theirradiation.

In particular embodiments, when the beam current “I_(beam)” is set foreach spot, the beam current at the dose monitor system for each spot iscalculated as follows. For each spot “spot_number”, the beam current“I_(beam)(spot_number)” may be calculated by of the fraction of theprescribed monitor unit value “MU” and the minimum spot duration“T_(min)”, and may be multiplied optionally with a factor “F”, whichdescribes the energy losses of the proton or ion beam in the dosemonitor system or any other dose monitor system specific correction. Anexample of a generalized, high level spot algorithm is described below:

Part 1 of Example Spot Algorithm:

l_(beam)(spot_number) = MU(spot_number)/T_(min) * F

In the next steps the treatment system limitations are taken intoaccount. As an example, the measurement range of the dose monitor systemand the beam position and beam shape monitor system, “I_min_monitors”and “I_max_monitors”, are considered.

Part 2 of Example Spot Algorithm:

  If l_(beam)(spot_number) > l_max_monitors then  l_(beam)(spot_number)= l_max_monitors Endif If l_(beam)(spot_number) < l_min_monitors then Error_with_identifier End if

As a further example, the maximum or minimum beam current at the dosemonitor system limited by the devices of the accelerator, and/or theenergy selection system, and/or beam transfer line are considered,“I_min” and “I_max.” For example, I_min may be the minimum possibleextracted beam current of the accelerator times the so-calledtransmission of the energy selection system and beam transfer line, andI_max may be the maximum possible extracted beam current of theaccelerator times the so-called transmission of the energy selectionsystem and beam transfer line.

Part 3 of Example Spot Algorithm:

  If l_(beam)(spot_number) > l_max then  l_(beam)(spot_number) = l_max If l_(beam)(spot_number) < l_min_monitors then   Error_with_identifier Endif Endif If l_(beam)(spot_number) < l_min then Error_with_identifier Endif

In the example algorithm directly above, the error messages should notoccur if the machine configuration of the treatment planning system, thetreatment system, and the measurement range of the treatment system dosemonitor system are designed correctly. Although the example algorithmconsiders particular example system limitations, any other suitablelimitations can be taken into account by plugging them into any suitablecombination of Parts 2 and 3 of the example algorithm.

In the next step, the algorithm may calculate either the beam current(or number of protons or ions per second) from the accelerator,I_(accelerator), or the number of extracted protons or ions per timesegment from the accelerator, N_(accelerator). In the equations below,“S” is the ratio between the beam current at the dose monitor systemI_(beam) and the beam current from the accelerator I_(accelerator), and“time_segment” is the duration of one or more time segments during whichthe accelerator extracts protons or ions. S may depend on the energy,the Gantry angle, and/or the beam spot size.

i. Part 4 of Spot Algorithm:

l_(accelerator)(spot_number) = l_(beam)(spot_number)/S

or

ii.

N _(accelerator)(spot_number) = l_(beam)(spot_number)/S * time_segment

iii. Part 5 of Example Spot Algorithm:

iv.

T(spot_number) = MU(spot_number)/  l_(beam)(layer_number) * F

The ratio “S” depends of the implementation of the treatment machine,for example it can depend on the beam energy of the layer, one or moretreatment machine limitations and/or one or more treatment machineparameters. T(spot_number) may be the duration of each spot during theirradiation.

In particular embodiments, in the example algorithms (layer and spotalgorithms) describe above, the minimum spot duration “T_(min)” may havea value of any suitable range. For example, it may be in the range ofmilliseconds. More generally, it may for example, range from 1 μs toseveral seconds, depending on the design of the treatment system.

All determined machine parameter from the treatment plan including thebeam current or number of protons (or ions) per second from theaccelerator may be calculated by the algorithm, described herein.

FIG. 9 illustrates an example computer system 900 that may be used toexecute the instructions involved in the algorithm used for irradiatinga target in a time-optimized manner. In particular embodiments, one ormore computer systems 900 may perform one or more steps of one or moremethods described or illustrated herein. In particular embodiments, oneor more computer systems 900 may provide functionality described orillustrated herein. In particular embodiments, software running on oneor more computer systems 900 may perform one or more steps of one ormore methods described or illustrated herein or provide functionalitydescribed or illustrated herein. Particular embodiments may include oneor more portions of one or more computer systems 900. Herein, referenceto a computer system may encompass a computing device, and vice versa,where appropriate. Moreover, reference to a computer system mayencompass one or more computer systems, where appropriate.

This disclosure contemplates any suitable number of computer systems900. This disclosure contemplates computer system 900 taking anysuitable physical form. As example and not by way of limitation,computer system 900 may be an embedded computer system, a system-on-chip(SOC), a single-board computer system (SBC) (such as, for example, acomputer-on-module (COM) or system-on-module (SOM)), a desktop computersystem, a laptop or notebook computer system, an interactive kiosk, amainframe, a mesh of computer systems, a mobile telephone, a personaldigital assistant (PDA), a server, a tablet computer system, anaugmented/virtual reality device, or a combination of two or more ofthese. Where appropriate, computer system 900 may include one or morecomputer systems 900; be unitary or distributed; span multiplelocations; span multiple machines; span multiple data centers; or residein a cloud, which may include one or more cloud components in one ormore networks. Where appropriate, one or more computer systems 900 mayperform without substantial spatial or temporal limitation one or moresteps of one or more methods described or illustrated herein. As anexample and not by way of limitation, one or more computer systems 900may perform in real-time or in batch mode one or more steps of one ormore methods described or illustrated herein. One or more computersystems 900 may perform at different times or at different locations oneor more steps of one or more methods described or illustrated herein,where appropriate.

In particular embodiments, computer system 900 may include a processor902, memory 904, storage 906, an input/output (I/O) interface 908, acommunication interface 910, and a bus 912. Although this disclosuredescribes and illustrates a particular computer system having aparticular number of particular components in a particular arrangement,this disclosure contemplates any suitable computer system having anysuitable number of any suitable components in any suitable arrangement.

In particular embodiments, processor 902 may include hardware forexecuting instructions, such as those making up a computer program. Asan example and not by way of limitation, to execute instructions,processor 902 may retrieve (or fetch) the instructions from an internalregister, an internal cache, memory 904, or storage 906; decode andexecute them; and then write one or more results to an internalregister, an internal cache, memory 904, or storage 906. In particularembodiments, processor 902 may include one or more internal caches fordata, instructions, or addresses. This disclosure contemplates processor902 including any suitable number of any suitable internal caches, whereappropriate. As an example and not by way of limitation, processor 902may include one or more instruction caches, one or more data caches, andone or more translation lookaside buffers (TLBs). Instructions in theinstruction caches may be copies of instructions in memory 904 orstorage 906, and the instruction caches may speed up retrieval of thoseinstructions by processor 902. Data in the data caches may be copies ofdata in memory 904 or storage 906 for instructions executing atprocessor 902 to operate on; the results of previous instructionsexecuted at processor 902 for access by subsequent instructionsexecuting at processor 902 or for writing to memory 904 or storage 906;or other suitable data. The data caches may speed up read or writeoperations by processor 902. The TLBs may speed up virtual-addresstranslation for processor 902. In particular embodiments, processor 902may include one or more internal registers for data, instructions, oraddresses. This disclosure contemplates processor 902 including anysuitable number of any suitable internal registers, where appropriate.Where appropriate, processor 902 may include one or more arithmeticlogic units (ALUs); be a multi-core processor; or include one or moreprocessors 902. Although this disclosure describes and illustrates aparticular processor, this disclosure contemplates any suitableprocessor.

In particular embodiments, memory 904 may include main memory forstoring instructions for processor 902 to execute or data for processor902 to operate on. As an example and not by way of limitation, computersystem 900 may load instructions from storage 906 or another source(such as, for example, another computer system 900) to memory 904.Processor 902 may then load the instructions from memory 904 to aninternal register or internal cache. To execute the instructions,processor 902 may retrieve the instructions from the internal registeror internal cache and decode them. During or after execution of theinstructions, processor 902 may write one or more results (which may beintermediate or final results) to the internal register or internalcache. Processor 902 may then write one or more of those results tomemory 904. In particular embodiments, processor 902 executes onlyinstructions in one or more internal registers or internal caches or inmemory 904 (as opposed to storage 906 or elsewhere) and operates only ondata in one or more internal registers or internal caches or in memory904 (as opposed to storage 906 or elsewhere). One or more memory buses(which may each include an address bus and a data bus) may coupleprocessor 902 to memory 904. Bus 912 may include one or more memorybuses, as described below. In particular embodiments, one or more memorymanagement units (MMUs) reside between processor 902 and memory 904 andfacilitate accesses to memory 904 requested by processor 902. Inparticular embodiments, memory 904 includes random access memory (RAM).This RAM may be volatile memory, where appropriate. Where appropriate,this RAM may be dynamic RAM (DRAM) or static RAM (SRAM). Moreover, whereappropriate, this RAM may be single-ported or multi-ported RAM. Thisdisclosure contemplates any suitable RAM. Memory 904 may include one ormore memories 904, where appropriate. Although this disclosure describesand illustrates particular memory, this disclosure contemplates anysuitable memory.

In particular embodiments, storage 906 may include mass storage for dataor instructions. As an example and not by way of limitation, storage 906may include a hard disk drive (HDD), a floppy disk drive, flash memory,an optical disc, a magneto-optical disc, magnetic tape, or a UniversalSerial Bus (USB) drive or a combination of two or more of these. Storage906 may include removable or non-removable (or fixed) media, whereappropriate. Storage 906 may be internal or external to computer system900, where appropriate. In particular embodiments, storage 906 isnon-volatile, solid-state memory. In particular embodiments, storage 906includes read-only memory (ROM). Where appropriate, this ROM may bemask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM),electrically erasable PROM (EEPROM), electrically alterable ROM (EAROM),or flash memory or a combination of two or more of these. Thisdisclosure contemplates mass storage 906 taking any suitable physicalform. Storage 906 may include one or more storage control unitsfacilitating communication between processor 902 and storage 906, whereappropriate. Where appropriate, storage 906 may include one or morestorages 906. Although this disclosure describes and illustratesparticular storage, this disclosure contemplates any suitable storage.

In particular embodiments, I/O interface 908 may include hardware,software, or both, providing one or more interfaces for communicationbetween computer system 900 and one or more I/O devices. Computer system900 may include one or more of these I/O devices, where appropriate. Oneor more of these I/O devices may enable communication between a personand computer system 900. As an example and not by way of limitation, anI/O device may include a keyboard, keypad, microphone, monitor, mouse,printer, scanner, speaker, still camera, stylus, tablet, touch screen,trackball, video camera, another suitable I/O device or a combination oftwo or more of these. An I/O device may include one or more sensors.This disclosure contemplates any suitable I/O devices and any suitableI/O interfaces 908 for them. Where appropriate, I/O interface 908 mayinclude one or more device or software drivers enabling processor 902 todrive one or more of these I/O devices. I/O interface 908 may includeone or more I/O interfaces 908, where appropriate. Although thisdisclosure describes and illustrates a particular I/O interface, thisdisclosure contemplates any suitable I/O interface.

In particular embodiments, communication interface 910 may includehardware, software, or both providing one or more interfaces forcommunication (such as, for example, packet-based communication) betweencomputer system 900 and one or more other computer systems 900 or one ormore networks. As an example and not by way of limitation, communicationinterface 910 may include a network interface controller (NIC) ornetwork adapter for communicating with an Ethernet or other wire-basednetwork or a wireless NIC (WNIC) or wireless adapter for communicatingwith a wireless network, such as a WI-FI network. This disclosurecontemplates any suitable network and any suitable communicationinterface 910 for it. As an example and not by way of limitation,computer system 900 may communicate with an ad hoc network, a personalarea network (PAN), a local area network (LAN), a wide area network(WAN), a metropolitan area network (MAN), or one or more portions of theInternet or a combination of two or more of these. One or more portionsof one or more of these networks may be wired or wireless. As anexample, computer system 900 may communicate with a wireless PAN (WPAN)(such as, for example, a BLUETOOTH WPAN), a WI-FI network, a WI-MAXnetwork, a cellular telephone network (such as, for example, a GlobalSystem for Mobile Communications (GSM) network), or other suitablewireless network or a combination of two or more of these. Computersystem 900 may include any suitable communication interface 910 for anyof these networks, where appropriate. Communication interface 910 mayinclude one or more communication interfaces 910, where appropriate.Although this disclosure describes and illustrates a particularcommunication interface, this disclosure contemplates any suitablecommunication interface.

In particular embodiments, bus 912 may include hardware, software, orboth coupling components of computer system 900 to each other. As anexample and not by way of limitation, bus 912 may include an AcceleratedGraphics Port (AGP) or other graphics bus, an Enhanced Industry StandardArchitecture (EISA) bus, a front-side bus (FSB), a HYPERTRANSPORT (HT)interconnect, an Industry Standard Architecture (ISA) bus, an INFINIBANDinterconnect, a low-pin-count (LPC) bus, a memory bus, a Micro ChannelArchitecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, aPCI-Express (PCIe) bus, a serial advanced technology attachment (SATA)bus, a Video Electronics Standards Association local (VLB) bus, oranother suitable bus or a combination of two or more of these. Bus 912may include one or more buses 912, where appropriate. Although thisdisclosure describes and illustrates a particular bus, this disclosurecontemplates any suitable bus or interconnect.

Herein, a computer-readable non-transitory storage medium or media mayinclude one or more semiconductor-based or other integrated circuits(ICs) (such, as for example, field-programmable gate arrays (FPGAs) orapplication-specific ICs (ASICs)), hard disk drives (HDDs), hybrid harddrives (HHDs), optical discs, optical disc drives (ODDs),magneto-optical discs, magneto-optical drives, floppy diskettes, floppydisk drives (FDDs), magnetic tapes, solid-state drives (SSDs),RAM-drives, SECURE DIGITAL cards or drives, any other suitablecomputer-readable non-transitory storage media, or any suitablecombination of two or more of these, where appropriate. Acomputer-readable non-transitory storage medium may be volatile,non-volatile, or a combination of volatile and non-volatile, whereappropriate.

Herein, “or” is inclusive and not exclusive, unless expressly indicatedotherwise or indicated otherwise by context. Therefore, herein, “A or B”means “A, B, or both,” unless expressly indicated otherwise or indicatedotherwise by context. Moreover, “and” is both joint and several, unlessexpressly indicated otherwise or indicated otherwise by context.Therefore, herein, “A and B” means “A and B, jointly or severally,”unless expressly indicated otherwise or indicated otherwise by context.

The scope of this disclosure encompasses all changes, substitutions,variations, alterations, and modifications to the example embodimentsdescribed or illustrated herein that a person having ordinary skill inthe art would comprehend. The scope of this disclosure is not limited tothe example embodiments described or illustrated herein. Moreover,although this disclosure describes and illustrates respectiveembodiments herein as including particular components, elements,feature, functions, operations, or steps, any of these embodiments mayinclude any combination or permutation of any of the components,elements, features, functions, operations, or steps described orillustrated anywhere herein that a person having ordinary skill in theart would comprehend. Furthermore, reference in the appended claims toan apparatus or system or a component of an apparatus or system beingadapted to, arranged to, capable of, configured to, enabled to, operableto, or operative to perform a particular function encompasses thatapparatus, system, component, whether or not it or that particularfunction is activated, turned on, or unlocked, as long as thatapparatus, system, or component is so adapted, arranged, capable,configured, enabled, operable, or operative. Additionally, although thisdisclosure describes or illustrates particular embodiments as providingparticular advantages, particular embodiments may provide none, some, orall of these advantages.

What is claimed is:
 1. A method performed by one or more devices,comprising: receiving treatment information relating to a treatment planfor proton or ion-beam therapy to irradiate a target tissue; receivinginformation associated with the proton or ion-beam therapy; determininga beam current for a proton or ion beam based on the treatmentinformation and the information, wherein the beam current is determinedby considering a time required to deliver certain dose to the targettissue; and generating a control signal to cause a treatment machine toprovide the proton or ion beam after the beam current is determined;wherein the information relates to a parameter involved with anoperation of a particle-accelerator of the treatment machine.
 2. Themethod of claim 1, wherein the treatment plan specifies one or more of:a target volume of the target tissue; a prescribed beam position in x-and y-coordinates per spot at an isocenter, wherein the x- andy-coordinates are transversal to a beam direction, a prescribed energyof the proton or ion beam per spot, and a prescribed amount of monitorunits per spot; a set of field parameters that specify a direction fromwhich the proton or ion beam is to be shot, a position of the targetvolume, and treatment specific parameters for one or more fields; afraction parameter that specifies a portion of treatment dose that is tobe delivered for a given treatment session; or a combination of theforegoing.
 3. The method of claim 1, wherein the parameter comprises amachine parameter of a dose-monitor system involved in the proton or ionbeam therapy, and wherein the machine parameter of the dose-monitorsystem is a beam parameter that the dose-monitor system is configured tomonitor.
 4. The method of claim 1, wherein the parameter comprises amachine parameter of a beam-position and beam-shape monitoring systeminvolved in the proton or ion beam therapy, and wherein the machineparameter of the beam-position and beam-shape monitoring system is abeam parameter that the beam-position and beam-shape monitoring systemis configured to monitor.
 5. The method of claim 1, wherein theinformation relates to a maximum beam current.
 6. The method of claim 1,wherein the determining of the beam current comprises: determining atime of exposure required to deliver a prescribed value of monitorunits; calculating a ratio based on the prescribed value of monitorunits and the determined time of exposure; and if the ratio meets acertain criterion, setting the beam current to a certain beam currentlevel.
 7. The method of claim 1, wherein the parameter comprises aparameter of the particle-accelerator, and wherein the beam current isdetermined based on the parameter of the particle-accelerator.
 8. Themethod of claim 1, further comprising determining a spot duration basedon the beam current.
 9. The method of claim 8, wherein the spot durationis for a spot at the target tissue.
 10. The method of claim 1, whereinthe determining of the beam current comprises: determining a time ofexposure required to deliver an amount of treatment dose; calculating aratio based on the amount of treatment dose and the determined time ofexposure; and if the ratio meets a criterion, setting the beam currentto a certain beam current level.
 11. The method of claim 1, wherein theparameter comprises a machine parameter of the particle-accelerator, andwherein the information relates to the machine parameter of aparticle-accelerator.
 12. The method of claim 1, wherein the timerequired to deliver the certain dose to the target tissue comprises atime required to deliver a certain quantity of monitor units to one ormore of a plurality of spots, and wherein the spots are defined in thetreatment plan.
 13. The method of claim 1, wherein the beam current isdetermined by considering a time required to deliver certain dose to aparticular area of the target tissue, and wherein the particular area isan energy layer defined by one or more z-locations of a target volumeprescribed in the treatment plan.
 14. The method of claim 1, furthercomprising: monitoring the proton or ion beam, and an amount of monitorunits delivered to the target tissue; and adjusting a position of theproton or ion beam, an intensity of the proton or ion beam, a depth ofthe proton beam, or a combination of the foregoing.
 15. The method ofclaim 1, wherein the target tissue is diseased tissue.
 16. The method ofclaim 1, wherein the treatment machine comprises a cyclotron or asynchrotron.
 17. The method of claim 1, wherein the proton or ion beamis for delivery to a particular area of the target tissue.
 18. A systemcomprising: one or more processors; and one or more computer-readablenon-transitory storage media coupled to the one or more of theprocessors, the one or more computer-readable non-transitory storagemedia comprising instructions, which when executed by the one or moreprocessors, will cause the system to: receive treatment informationrelating to a treatment plan for proton or ion-beam therapy to irradiatea target tissue; receive information associated with the proton orion-beam therapy; determine a beam current for a proton or ion beambased on the treatment information and the information, wherein the beamcurrent is determined by considering a time required to deliver certaindose to the target tissue; and generate a control signal to cause atreatment machine to provide the proton or ion beam after the beamcurrent is determined; wherein the information relates to a parameterinvolved with an operation of a particle-accelerator of the treatmentmachine.
 19. The system of claim 18, wherein the information relates toa machine parameter of: a particle-accelerator; a dose-monitor systeminvolved in the proton or ion beam therapy, wherein the machineparameter of the dose-monitor system is a beam parameter that thedose-monitor system is configured to monitor; or a beam-position andbeam-shape monitoring system involved in the proton or ion beam therapy,wherein the machine parameter of the beam-position and beam-shapemonitoring system is a beam parameter that the beam-position andbeam-shape monitoring system is configured to monitor.
 20. One or morecomputer-readable non-transitory storage media comprising one or moreinstructions, which when executed by one or more devices, will cause amethod to be performed, the method comprising: receiving treatmentinformation relating to a treatment plan for proton or ion-beam therapyto irradiate a target tissue; receiving information associated with theproton or ion-beam therapy; determining a beam current for a proton orion beam based on the treatment information and the information, whereinthe beam current is determined by considering a time required to delivercertain dose to the target tissue; and generating a control signal tocause a treatment machine to provide the proton or ion beam after thebeam current is determined; wherein the information relates to aparameter involved with an operation of a particle-accelerator of thetreatment machine.